Carboxylic anhydrides play important roles in industry due to their diverse applications in pharmaceuticals, polymers and dyes, etc. In synthesis, carboxylic anhydrides are common functional groups with high reactivity, thus, they are often used as substrates and intermediates in the production of a variety of functional groups especially carboxylic derivatives. However, conventional methods for preparing carboxylic anhydrides usually require highly reactive acyl halides or harsh conditions. In this study, we provide a novel reaction to synthesize carboxylic anhydrides from the stable tert-butyl esters. With the use of α,α-dichlorodiphenylmethane as chloride source and tin (II) chloride as catalyst, this reaction can be conducted under room temperature and afforded a variety of target carboxylic anhydrides in high yields, providing an efficient method to synthesize these compounds under mild conditions.